Simplified Calculation of the Average Number of Radicals Per Particle in Emulsion Polymerization: Effect of Particle Nucleation and Coagulation Rates

다국어 초록 (Multilingual Abstract)

The solutions available for the well‐known Smith–Ewart recurrence equation (assuming size monodispersity) for calculating the average number of radicals per particle (n¯) do not consider the contribution of nucleation and coagulation of active particles. Notwithstanding this limitation, they are often used to calculate n¯ in simplified mathematical models for commercial simulation software of industrial processes or for process control purposes. In this work, algebraic equations to calculate n¯ for 0–1 systems that consider such contributions are developed. It is found that in the nucleation stage under typical conditions of emulsion polymerization, if nucleation and coagulation of particles are not considered in the calculation of n¯, it could lead to large errors although its effect still needs to be evaluated in other relevant process parameters as well. However, such significant error could be present for a case of study where secondary nucleation and limited coagulation is experimentally detected.
If nucleation and coagulation are not considered in the calculation of the average number of radicals per particle in emulsion polymerization (as it is often done in simplified mathematical models), large errors can be obtained for typical conditions, as it is shown in the figure.